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Square Kilometre Array Science. Stephen Fine SKA Fellow University of the Western Cape. SKA Science goals. Cosmology + Galaxy evolution Testing general relativity: gravity waves Magnetic fields in the Universe Exoplanets and SETI The first light in the Universe…….EVER?.
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Square Kilometre ArrayScience Stephen Fine SKA Fellow University of the Western Cape
SKA Science goals • Cosmology + Galaxy evolution • Testing general relativity: gravity waves • Magnetic fields in the Universe • Exoplanets and SETI • The first light in the Universe…….EVER?
Cosmology + Galaxy evolution `If you want to make an apple pie from scratch, you must first create the Universe.’ `You have to know the past to understand the present.’ Carl Sagan (1935-1996)
Telescopes as time machines Speed of light: 299,792 km/s You see this slide ~ 0.00000003 seconds (30 nanoseconds) in the past. Astronomers like distances measured in lightyears 1 ly = 9,460,000,000,000 km
Telescopes as time machines Proximacentauri 4.24 ly
Telescopes as time machines Proximacentauri 4.24 ly
Telescopes as time machines Eta Carina 7500-8000 ly
Telescopes as time machines Andromeda galaxy 2.2 Mly
Cosmic timeline Earth Distance = 0 ly Age = 13.7 billion years Big Bang Distance = 13.7 billion ly Age = 0 Between here is the whole history of cosmic evolution
Back to galaxy evolution In the nearby Universe we have a fairly good understanding of the demographics of galaxies. 0.4 billion years
Galaxy evolution Stepping out we have optical surveys that can find large numbers of galaxies when the universe was ~4/5th its current age. 2.5 billion years
Galaxy evolution With the largest telescopes we can find massive galaxies when the Universe was ~1/10th its current age. 12.7 billion years 1 billion years after BB
Galaxy evolution We know that galaxies had not started forming until at least 0.2 billion years after the Big Bang. 13.5 billion years 0.2 billion years after BB
The state of the art Some massive galaxies formed Limit of current galaxy mass surveys Limit of current large galaxy surveys No galaxies
Enter the SKA Some massive galaxies formed Limit of current galaxy mass surveys Limit of current large galaxy surveys No galaxies Will detect `typical’ Milky Way type objects as they are first forming A mass survey over half the observable Universe
Enter the SKA Some massive galaxies formed Limit of current galaxy mass surveys Limit of current large galaxy surveys No galaxies Will detect `typical’ Milky Way type objects as they are first forming A mass survey over half the observable Universe
Project Cyclops Remind you of anything?
Some estimates for SKA SETI Terrestrial TV/radio • Could be observed from ~75 ly • ~2500 stars in that volume • ~250 are sun like. • (Most others too faint)
Some estimates for SKA SETI Radar (especially military) • Could be observed from a few hundred ly • ~10000 stars in that volume • ~1000 are sun like.